off your gullet

Extremely intoxicated to the point of no return.

Your gullet is a funny word to describe your mouth, throat, and stomach region, hence an individual who is off their gullet may be projectile vomiting as a result of being so intoxicated

Frat guy: “Dude you gotta get up, your ride is here!”

Dude who is fighting for his life on the toilet: “I literally can’t guy, I’m off my gullet.”

His ride: “How much have you drank dude? You are off your gullet!”